Ophthalmic apparatus with corrective meridians having extended tolerance band

ABSTRACT

The embodiments disclosed herein include improved toric lenses and other ophthalmic apparatuses (including, for example, contact lens, intraocular lenses (IOLs), and the like) that includes one or more refractive angularly-varying phase members, each varying depths of focus of the apparatus so as to provide an extended tolerance to misalignments of the apparatus. Each refractive angularly-varying phase member has a center at a first meridian (e.g., the intended correction meridian) that directs light to a first point of focus (e.g., at the retina of the eye). At angular positions nearby to the first meridian, the refractive angularly-varying phase member directs light to points of focus of varying depths and nearby to the first point of focus such that rotational offsets of the multi-zonal lens body from the center of the first meridian directs light from the nearby points of focus to the first point of focus.

RELATED APPLICATIONS

This application is a divisional of and claims priority to U.S. patentapplication Ser. No. 15/467,550, filed Mar. 23, 2017, which claimspriority to, and the benefit of, U.S. Provisional Appl. No. 62/312,321,filed Mar. 23, 2016, and U.S. Provisional Appl. No. 62/312,338, filedMar. 23, 2016, each of which is incorporated by reference herein in itsentirety.

TECHNICAL FIELD

This application is directed to lenses for correcting astigmatism,including providing increased tolerance for lens placement duringimplantation.

BACKGROUND

Ophthalmic lenses, such as spectacles, contact lenses and intraocularlenses, may be configured to provide both spherical and cylinder power.The cylinder power of a lens is used to correct the rotationalasymmetric aberration of astigmatism of the cornea or eye, sinceastigmatism cannot be corrected by adjusting the spherical power of thelens alone. Lenses that are configured to correct astigmatism arecommonly referred to as toric lenses. As used herein, a toric lens ischaracterized by a base spherical power (which may be positive,negative, or zero) and a cylinder power that is added to the basespherical power of the lens for correcting astigmatism of the eye.

Toric lenses typically have at least one surface that can be describedby an asymmetric toric shape having two different curvature values intwo orthogonal axes, wherein the tonic lens is characterized by a “lowpower meridian” with a constant power equal to the base spherical powerand an orthogonal “high power meridian” with a constant power equal tothe base spherical power plus the cylinder power of the lens.Intraocular lenses, which are used to replace or supplement the naturallens of an eye, may also be configured to have a cylinder power forreducing or correcting astigmatism of the cornea or eye.

Existing toric lenses are designed to correct astigmatic effects byproviding maximum cylindrical power that precisely matches the cylinderaxis. Haptics are used to anchor an intraocular lens to maintain thelenses at a desired orientation once implanted in the eye. However,existing toric lenses themselves are not designed to account formisalignment of the lens that may occur during the surgical implantationof the lens in the eye or to account for unintended post-surgicalmovement of the lens in the eye.

Accordingly, it would be desirable to have intraocular lenses that aretolerant to misalignments.

SUMMARY

The embodiments disclosed herein include improved toric lenses and otherophthalmic apparatuses (including, for example, contact lens,intraocular lenses (IOLs), and the like) and associated method for theirdesign and use. In an embodiment, an ophthalmic apparatus (e.g., a toriclens) includes one or more angularly-varying phase members comprising adiffractive or refractive structure, each varying the depths of focus ofthe apparatus so as to provide an extended tolerance to misalignment ofthe apparatus when implanted in an eye. That is, the ophthalmicapparatus establishes a band of operational meridian over the intendedcorrection meridian.

In some embodiments, the ophthalmic apparatus includes a multi-zonallens body having a plurality of optical zones, where the multi-zonallens body forms the angularly-varying phase member. Eachangularly-varying phase member has a center at a first meridian (e.g.,the intended correction meridian) that directs light to a first point offocus (e.g., at the retina of the eye). At angular positions nearby tothe first meridian, the angularly-varying phase member directs light topoints of focus of varying depths and nearby to the first point of focussuch that rotational offsets of the multi-zonal lens body from thecenter of the first meridian directs light from the nearby points offocus to the first point of focus. In some embodiments, theangularly-varying phase member includes a combination of angularly andzonally refractive (or diffractive) phase structure. This structure, insome embodiments, has a height profile (in relation to the face of thelens) that gradually varies along the angular position (i.e., at nearbymeridian of the first meridian up) to provide off-axis operation up to apre-defined angular position (e.g., about ±5° or more from the firstmeridian). In some embodiments, the height profile T1(r, θ) for theangularly-varying phase member at each meridian θ is defined as T1(r,θ)=t₁(r)·|COS²(θ)|+t₂(r)·|SIN²(θ)|, where t₁(r) and t₂(r) are stepheights that matches an optical path difference (OPD) from −2λ to 2λ,where λ is the design wavelength at a zonal radius r. Put another way,each step heights t₁(r) and t₂(r) corresponds to a respective maximumand a minimum height (i.e., the peak and trough) of theangularly-varying phase member. In some embodiments, the angularly andzonally refractive phase structure (or angularly and zonally diffractivephase structure) varies along each meridian between the first meridian(which has the step height t₁(r)) and meridian that are, in someembodiments, about 45 degrees and about −45 degrees to the firstmeridian. It is contemplated that the angularly-varying phase member maybe purely refractive or a hybrid of diffractive and refractive. It isalso contemplated that angularly-varying phase members may comprise ofdifferent materials such as a stacking lens, where each layer iscomprised of a different material. It is further contemplated that theangularly-varying phase members may be comprised of a material ormaterials that have a variation in refractive index, a gradient index,or a programmed index, for example liquid crystal which creates therefractive change.

In some embodiments, the angularly-varying phase member establishes theband of operational meridian across a range selected from the groupconsisting of about ±4 degrees, about ±5 degrees, about ±6 degrees,about ±7 degrees, about ±8 degrees, about ±9 degrees, about ±10 degrees,about ±11 degrees, about ±12 degrees, about ±13, degrees, about ±14degrees, and about ±15 degrees.

In some embodiments, the multi-zonal lens body forms a secondangularly-varying phase member at a second meridian that is orthogonalto the first meridian. The second angularly-varying phase member, insome embodiments, varies along each meridian nearby to the center of thesecond meridian i) between the second meridian and meridians that are,in some embodiments, about 45 degrees and about −45 degrees to thesecond meridian. In some embodiments, the first and secondangularly-varying phase members form a butterfly pattern.

The first angularly-varying phase member and the secondangularly-varying phase member, in some embodiments, form an angularlyvarying efficiency bifocal optics.

In some embodiments, the multi-zonal lens body includes at least threeoptical zones that forms an angularly varying efficiency trifocaloptics, e.g., a diffractive trifocal optics or a refractive trifocaloptics. In some embodiments, the multi-zonal lens body forms anangularly varying efficiency quadric optics e.g., a diffractive quadricoptics or a refractive quadric optics. In some embodiments, themulti-zonal lens body forms an angularly varying efficiency multi-focaloptic e.g., a diffractive multi-focal optic or a refractive multi-focaloptic.

In some embodiments, the angularly-varying phase member at the firstmeridian comprises a monofocal lens. In some embodiments, the secondangularly-varying phase member at the second meridian comprises a secondmonofocal lens. In some embodiments, each of the meridians located atabout 45 degrees and about −45 degrees to the first meridian comprises abifocal lens, e.g., a diffractive bifocal optics or a refractive bifocaloptics.

In some embodiments, the angularly-varying phase structure of themulti-zonal lens body includes a first angularly-varying phase structure(e.g., formed by a first diffractive or refractive structure) at a firstmeridian (e.g., the 0-degree meridian), a second angularly-varying phasestructure at a second meridian (e.g., the 45-degree meridian) (e.g.,formed by second a diffractive or refractive structure), and a thirdangularly-varying phase structure at a third meridian (e.g., −45-degreemeridian) (e.g., formed by a third diffractive or refractive structure),wherein the first angularly-varying phase structure has a first point offocus and each of the second angularly-varying phase structure and thethird angularly-varying phase structure has a respective point of focusnearby to the first point of focus, and wherein the secondangularly-varying phase structure has a light transmission or fociefficiency (e.g., about 50%) different from that of the firstangularly-varying phase structure. In some embodiments, the secondangularly-varying phase structure has a second light transmission orfoci efficiency.

In some embodiments, the ophthalmic apparatus includes a plurality ofalignment markings, including a first set of alignment markings and asecond set of alignment markings. The first set of alignment markingscorresponds to the center of the first meridian, and the second set ofalignment markings corresponds to the band of operational meridian.

In another aspect, a rotationally-tolerant ophthalmic apparatus (e.g.,toric intraocular lens) having an established band of operationmeridians (e.g., at least about ±4 degrees or more) for placement overan intended astigmatism meridian is disclosed. The ophthalmic apparatusincludes a multi-zonal lens body having a plurality of optical zones,where the multi-zonal lens body forms the angularly-varying phasemember. The angularly-varying phase member has a center at anastigmatism correction meridian that directs light to a first point offocus (e.g., on the retina). At angular positions nearby to theastigmatism correction meridian, the portion of the angularly-varyingphase member at such angular positions directs light to points of focusof varying depths and nearby to the first point of focus such thatrotational offsets of the multi-zonal lens body from the center of theastigmatism correction meridian directs light from the nearby points offocus to the first point of focus.

In another aspect, a rotationally-tolerant ophthalmic apparatus forcorrecting astigmatism is disclosed. The ophthalmic apparatus includesan astigmatism correcting meridian that corresponds to a peak cylinderpower associated with a correction of an astigmatism. Therotationally-tolerant ophthalmic apparatus may include a plurality ofexterior alignment markings, including a first set of alignment markingsand a second set of alignment markings. The first set of alignmentmarkings corresponds to the astigmatism correcting meridian, and thesecond set of alignment markings corresponds to an operation band of therotationally-tolerant ophthalmic apparatus.

BRIEF DESCRIPTION OF THE DRAWINGS

Embodiments of the present invention may be better understood from thefollowing detailed description when read in conjunction with theaccompanying drawings. Such embodiments, which are for illustrativepurposes only, depict novel and non-obvious aspects of the invention.The drawings include the following figures:

FIGS. 1A and 1B are diagrams of an exemplary ophthalmic apparatus (e.g.,an intraocular toric lens) that includes angularly-varying phase members(reflective, diffractive, or both) that each provides an extendedrotational tolerance of the apparatus in accordance with an illustrativeembodiment.

FIGS. 2A, 2B, 2C, 2D, 2E, and 2F, each illustrates a plurality ofexemplary height profiles of the anterior or posterior face of theophthalmic apparatus of FIGS. 1A-1B in accordance with an illustrativeembodiment.

FIG. 3 is a schematic drawing of a top view of a human eye, in which thenatural lens of the eye has been removed and replaced with an ophthalmicapparatus that includes angularly-varying phase members in accordancewith an illustrative embodiment.

FIGS. 4A, 4B, 4C, and 4D are schematic diagrams of exemplary ophthalmicapparatuses that include either refractive or diffractiveangularly-varying phase members, in accordance with an illustrativeembodiment.

FIGS. 5A 5B are plots illustrating performance of a conventional toriclens designed to apply maximum cylinder power at a corrective meridianwhen subjected to rotational misalignment.

FIGS. 6A and 6B show plots of off-axis performances of an exemplaryophthalmic apparatus (diffractive or refractive) that includesangularly-varying phase members in accordance with an illustrativeembodiment.

FIGS. 7A and 7B are diagrams of an exemplary ophthalmic apparatus thatincludes angularly-varying phase members in accordance with anotherillustrative embodiment.

FIGS. 8 and 9 are diagrams illustrating height profiles of exemplaryophthalmic apparatuses of FIGS. 1A-1B and 7A-7B in accordance with theillustrative embodiments.

FIG. 10 is a diagram of an exemplary multi-focal lens ophthalmicapparatus that includes angularly-varying phase members in accordancewith another illustrative embodiment.

FIG. 11 is a diagram illustrating the multi-focal lens ophthalmicapparatus of FIG. 10 configured as a bifocal lens in accordance withanother illustrative embodiment.

FIG. 12 is a diagram illustrating the multi-focal lens ophthalmicapparatus of FIG. 10 configured as a tri-focal lens in accordance withanother illustrative embodiment.

FIG. 13 is a diagram of an exemplary ophthalmic apparatus that includesangularly-varying phase members (refractive, diffractive, or both) inaccordance with another illustrative embodiment.

FIG. 14 is a table of the ophthalmic apparatus of FIG. 13 configured asa tri-focal lens in accordance with another illustrative embodiment.

FIGS. 15A and 15B are diagrams of an exemplary ophthalmic apparatus thatincludes angularly-varying phase members with asymmetric height profilesin accordance with another illustrative embodiment.

FIGS. 16A, 16B, and 16C, each illustrates a plurality of exemplaryheight profiles of the ophthalmic apparatus of FIGS. 15A-15B inaccordance with an illustrative embodiment.

FIGS. 17A and 17B is a diagram of an exemplary ophthalmic apparatus thatincludes angularly-varying phase members and a symmetric height profilein accordance with another illustrative embodiment.

FIGS. 18A, 18B, and 18C, each illustrates a plurality of exemplaryheight profiles of the anterior or posterior face of the ophthalmicapparatus of FIGS. 17A and 17B in accordance with an illustrativeembodiment.

FIGS. 19A and 19B are diagrams of an exemplary ophthalmic apparatus thatincludes refractive angularly-varying phase members in accordance withanother illustrative embodiment.

FIGS. 20A, 20B, 20C, 20D, and 20E each illustrates a plurality ofexemplary height profiles of the anterior or posterior face of theophthalmic apparatus of FIGS. 19A-19B, in accordance with anillustrative embodiment.

FIGS. 21A, 21B, and 21C are diagrams illustrating an exemplaryophthalmic apparatus that includes refractive angularly-varying phasemembers, in accordance with another illustrative embodiment.

FIGS. 22A and 22B are diagrams illustrating a top and bottom view of anophthalmic apparatus of FIGS. 15A-15B with extended tolerance bandmarkers in accordance with an illustrative embodiment.

FIG. 23 is diagram of a method to generate, via a processor, the surfacewith the angularly-varying phase members, in accordance with anillustrative embodiment.

FIG. 24 is a diagram of an example computing device configured togenerate the surface with the angularly-varying phase members.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

Each and every feature described herein, and each and every combinationof two or more of such features, is included within the scope of thepresent invention provided that the features included in such acombination are not mutually inconsistent.

Embodiments of the present invention are generally directed to toriclenses or surface shapes, and/or related methods and systems forfabrication and use thereof. Toric lenses according to embodiments ofthe present disclosure find particular use in or on the eyes of human oranimal subjects. Embodiments of the present disclosure are illustratedbelow with particular reference to intraocular lenses; however, othertypes of lenses fall within the scope of the present disclosure.Embodiments of the present disclosure provide improved ophthalmic lens(including, for example, contact lenses, and intraocular lenses, corneallenses and the like) and include monofocal refractive lenses, monofocaldiffractive lenses, bifocal refractive lenses, bifocal diffractivelenses, and multifocal refractive lenses, multifocal diffractive lenses.

As used herein, the term “refractive optical power” or “refractivepower” means optical power produced by the refraction of light as itinteracts with a surface, lens, or optic. As used herein, the term“diffractive optical power” or “diffractive power” means optical powerresulting from the diffraction of light as it interacts with a surface,lens, or optic.

As used herein, the term “optical power” means the ability of a lens oroptics, or portion thereof, to converge or diverge light to provide afocus (real or virtual), and is commonly specified in units ofreciprocal meters (m⁻³) or Diopters (D). When used in reference to anintraocular lens, the term “optical power” means the optical power ofthe intraocular lens when disposed within a media having a refractiveindex of 1.336 (generally considered to be the refractive index of theaqueous and vitreous humors of the human eye), unless otherwisespecified. Except where noted otherwise, the optical power of a lens oroptic is from a reference plane associated with the lens or optic (e.g.,a principal plane of an optic). As used herein, a cylinder power refersto the power required to correct for astigmatism resulting fromimperfections of the cornea and/or surgically induced astigmatism.

As used herein, the terms “about” or “approximately”, when used inreference to a Diopter value of an optical power, mean within plus orminus 0.25 Diopter of the referenced optical power(s). As used herein,the terms “about” or “approximately”, when used in reference to apercentage (%), mean within plus or minus one percent (±1%). As usedherein, the terms “about” or “approximately”, when used in reference toa linear dimension (e.g., length, width, thickness, distance, etc.) meanwithin plus or minus one percent (1%) of the value of the referencedlinear dimension.

FIGS. 1A and 1B are diagrams of an exemplary ophthalmic apparatus 100(e.g., an intraocular toric lens) that includes angularly-varying phasemembers 102 (refractive, diffractive, or both) configured to provideextended rotational tolerance in accordance with an illustrativeembodiment.

The angularly-varying phase members have a center structure that appliescylinder power at a corrective meridian (e.g., the high power meridian).In FIGS. 1A and 1B, the corrective meridian is shown at Θ=0° and Θ=180°with the center structure being disposed at such Θ positions. Off-centerstructures of the angularly-varying phase members extend from the centerstructure in a gradually varying manner to apply cylinder power to aband of meridians surrounding the corrective meridian enabling theophthalmic apparatus to operate off-axis (or off-meridian) to thecorrective meridian (e.g., the astigmatism meridian). As shown in FIG.1A, the off-center structures extends, at least, from Θ=0° to Θ=10° andΘ=−10° to facilitate off-axis operation (from Θ=0°) up to ±10°. Theoff-center structures may extend from Θ=0° to Θ=90° and Θ=−90°. Thesemeridians may be referred to as a dynamic meridian.

Although the operational boundaries of the angularly varying phasemembers are shown to be at about ±10°, it is contemplated that otherangular values may be used, as are discussed herein. In addition, insome embodiments, it is also contemplated that operational boundariesmay be symmetrical or asymmetrical. For example, in certain embodiments,the operational boundaries may be skewed to one rotation, e.g., between+9° and −11° or, e.g., between +11° and −9°.

The angularly-varying phase members, in some embodiments, include anoptimized combination of angularly and zonally diffractive (orrefractive) phase structure located at each meridian to vary theextended depth of focus to a plurality of nearby focus points. Lightdirected to such nearby focus points are thus directed to the desiredfocus point when the ophthalmic apparatus is subjected to a rotationaloffset from a primary intended axis of alignment, thereby extending therotational tolerance of the apparatus to an extended tolerance band.This may also be referred to as “extended tolerance astigmatism band” or“extended misalignment band.” Remarkably, this extended toleranceastigmatism band delivers cylinder power to correct for the astigmatismfor a range of meridians (e.g., up to ±10° or more as shown in FIGS. 1Aand 1B), thereby eliminating any need for additional corrective measures(e.g., supplemental corrective devices or another surgical intervention)when the implanted ophthalmic apparatus is not perfectly aligned to thedesired astigmatism meridian in the eye.

Put another way, the angularly-varying phase members facilitate anextended band of the corrective meridian that has minimal, and/orclinically acceptable, degradation of the visual acuity and modulationtransfer function when the ophthalmic apparatus is subjected torotational misalignment between the astigmatic axis and a center axis ofthe corrective meridian.

In some embodiments, an exemplified toric IOL includes dynamic meridianor angularly varying efficiency quadric optics. In another embodiment,an exemplified toric IOL includes dynamic meridian or angularly varyingefficiency trifocal optics. In another embodiment, an exemplified toricIOL includes double dynamic meridian or angularly varying efficiencybifocal optics. In another embodiment, the bifocal or trifocal featuremay be disposed on one optical surface or on both optical surfaces of asingle optical lens or on any surfaces of a multiple optical elementsworking together as a system.

Referring still to FIGS. 1A and 1B, an embodiment of theangularly-varying phase members 102 is shown. In this embodiment, theangularly-varying phase members 102 are formed in multiple-zones (shownas zones 102 a, 102 b, 102 c), each forming a spatially-varying“butterfly” shaped structure centered around the optical axis 106. Themultiple-zone structure (102 a, 102 b, and 102 c), and angularly-varyingphase members 102 therein, form a first “high power meridian” (e.g.,having a constant power equal to the base spherical power plus acylinder power of the lens) at a first meridian (e.g., axis 110 shown asΘ=0° and Θ=180°) that corresponds to an axis of the eye to apply acorrection. The first corrective meridian 110 focuses light that passestherethrough to a first foci (i.e., point of focus) and is intended toalign with the astigmatic axis of the eye. At nearby meridians (e.g.,−10°, −9°, −8°, −7°, −6°, −5°, −4°, −3°, −2°, −1°, 1°, 2°, 3°, 4°, 5°,6°, 7°, 8°, 9°, and 10°), the angularly-varying phase members 102 focuslight that passes therethrough to a plurality of foci near the firstfoci. The angularly-varying phase members 102 vary from between thefirst meridian (Θ=0°) and another meridian located about 10 degrees fromthe first meridian (e.g., axis 114 shown as Θ=10°).

FIGS. 1A and 1B illustrate the exemplary ophthalmic apparatus 100 havinga diffractive surface 120. A diffractive surface comprises multipleechelette elements. In some embodiments, an intraocular lens, which hasa diffractive grating covering its entire surface, has between 15 and32, or more echelette elements. In some embodiments, the diffractivegrating includes more than 32 echelette elements. As shown in FIGS. 1Aand 1B, multiple echelette elements cover each region, or if there isone echelette element, or the echelette spans only a portion of theregion, then a refractive area will cover the rest of the region. Thoughshown here as a diffractive surface, the angularly varying phase membersare later illustrated as a refractive surface, as later discussedherein.

As shown in FIGS. 1A and 1B, both the heights (i.e., thicknesses) of thelens and the spatial sizes, at each zone, vary among the different axesto form the angularly-varying phase member 102. To illustrate thisstructure, both a first height profile 116 of the lens along the firstcorrective meridian (e.g., at Θ=0°) and a second height profile 118 ofthe lens along a lower power meridian (i.e., at axis 114 shown as Θ=10°)are presented at plots 108 a and 108 b, respectively, for each of FIGS.1A and 1B. The height profile of the lens varies at each axis as thefirst height profile 116 gradually transitions (e.g., as shown by thecurved profile 122) into the second height profile 118. The first andsecond height profiles 116 and 118 are illustrated relative to oneanother in a simplified format. It should be appreciated that there maybe multiple echelette elements (i.e., diffractive structures) in each ofthe multiple zone structures, surrounded by a refractive region.Alternatively, rather than relying on diffraction, one or more of themultiple zone structures may have only refraction surfaces to varypower.

It should also be appreciated that the height profiles herein areillustrated in a simplified form (e.g., as a straight line). The heightprofiles for each zone may form other surfaces—such as refractive,diffractive—or have other shapes—such convex, concave, or combinationsthereof. The profiles may be added to, or incorporated into, a base lensas, for example, shown in FIGS. 4A, 4B, 4C, and 4D. FIGS. 4A, 4B, 4C,and 4D are schematic diagrams of exemplary ophthalmic apparatuses thatinclude either refractive or diffractive angularly-varying phasemembers, in accordance with an illustrative embodiment.

Referring still to FIGS. 1A and 1B, the multiple-zone structure (e.g.,104 a, 104 b, and 104 c), and angularly-varying phase members 126therein, form a second “high power meridian” 112 (i.e., axis 112 shownas Θ=90°) which is orthogonal to the first corrective meridian 110. Thesecond corrective meridian 112 includes a second angularly varying phasestructure 126. In some embodiments, the second angularly varying phasestructure focuses light to a second set of foci (e.g., as part of amulti-focal lens configuration).

FIGS. 2A, 2B, 2C, 2D, 2E, and 2F, each illustrates a plurality of heightprofiles of the angularly-varying phase member 102 of FIGS. 1A and 1Bbetween the first high power meridian (at Θ=0°) and the operational edgeof the angularly varying phase members in accordance with anillustrative embodiment. In FIG. 2B, representative height profiles (ofan echelette element) at Θ=0° (202); Θ=2° (204); Θ=4° (206); Θ=6° (208);Θ=8° (210); and Θ=10° (212) (also shown in FIG. 2A) are provided ascross-sections of the echelette elements at the different meridiansshown in FIG. 2A. As shown, the height profiles at axes nearby to thefirst high power meridian (e.g., between ±10°) have a similar shape, asthe first high power meridian. The height profile varies in a continuousgradual manner (e.g., having a sine and cosine relationship) along theradial direction (e.g., at different radial values) and along theangular direction (e.g., at different angular positions). The varying ofthe angular position and of the radial position, e.g., between Θ=0° andΘ=10° and between Θ=0° and Θ=−10° forms the angularly varying phasemember. This can also be observed in FIGS. 2B and 2C. In FIGS. 2B and2C, the edge of an echelette element of the height profile of theangularly-varying phase member at Θ=2° (204) is shown to vary moreabruptly in relation to the center meridian at Θ=0° (202). The abrupttransition in the edge position is shown to transition more slowly atΘ=4° (206), and even more slowly at Θ=6° (208); then Θ=8° (210); andthen Θ=10° (212). In contrast, the height profile transitions moreslowly near the center meridian at Θ=0° and then more sharply at theedge. This transition may be described as a cosine-based or sine-basedfunction, a polynomial function, or a function derived from acombination thereof.

FIG. 2C illustrates a height profiles (near the optical axis and betweenthe operational boundaries of the angularly varying phase member 102) atΘ=0° (202); Θ=2° and −2° (204); Θ=4° and −4° (206); Θ=6° and −6° (208);Θ=8° and −8° (210); and Θ=10° and −10° (212) superimposed next to oneanother. This variation of the height profile along the radial axisprovides a lens region that focuses light at the desired foci and otherfoci nearby. To this end, radial offset (i.e., misalignment) of theophthalmic apparatus from the center axis of a desired correctivemeridian results in its nearby regions focusing the light to the desiredfoci. This effect is further illustrated in FIG. 3.

In FIGS. 2D, 2E, and 2F, example height profiles of the lens surfacebetween Θ=0° and Θ=45° are shown. As shown in FIGS. 2E and 2F, theheight profiles of the angularly varying phase member vary as acosine-based or sine-based function. In some embodiments, the heightprofiles of the lens surface between Θ=45° and Θ=90° are mirrored atΘ=45° to the lens surface between Θ=0° and Θ=45°.

FIG. 3 is a schematic drawing of a top view of a human eye 302, in whichthe natural lens of the eye 302 has been removed and replaced with anintraocular lens 100 (shown in simplified form in the upper portion ofFIG. 3 and in greater detail in the lower portion of FIG. 3). Lightenters from the left of FIG. 3, and passes through the cornea 304, theanterior chamber 306, the iris 308, and enters the capsular bag 310.Prior to surgery, the natural lens occupies essentially the entireinterior of the capsular bag 310. After surgery, the capsular bag 310houses the intraocular lens 100, in addition to a fluid that occupiesthe remaining volume and equalizes the pressure in the eye.

After passing through the intraocular lens, light exits the posteriorwall 312 of the capsular bag 310, passes through the posterior chamber328, and strikes the retina 330, which detects the light and converts itto a signal transmitted through the optic nerve 332 to the brain. Theintraocular lens 100 comprises an optic 324 and may include one or morehaptics 326 that are attached to the optic 324 and may serve to centerthe optic 324 in the eye and/or couple the optic 324 to the capsular bag310 and/or zonular fibers 320 of the eye.

The optic 324 has an anterior surface 334 and a posterior surface 336,each having a particular shape that contributes to the refractive ordiffractive properties of the lens. Either or both of these lenssurfaces may optionally have an element made integral with or attachedto the surfaces. FIGS. 4A, 4B, 4C, and 4D are schematic diagrams ofexemplary ophthalmic apparatuses that include either refractive ordiffractive angularly-varying phase members, in accordance with anillustrative embodiment. Specifically, FIGS. 4A and 4B show examples ofdiffractive lenses, and FIGS. 4C and 4D show examples of refractivelenses. The diffractive lenses or refractive lenses includes theangularly varying phase members as described herein. The refractiveand/or diffractive elements on the anterior and/or posterior surfaces,in some embodiments, have anamorphic or toric features that can generateastigmatism to offset the astigmatism from a particular cornea in aneye.

Referring still to FIG. 3, the intraocular lens 100 includesangularly-varying phase members (reflective, diffractive, or both) thatfocus at a plurality of focus points that are offset radially to oneanother so as to provide an extended tolerance to misalignments of thelens 100 when implanted into the eye 302. That is, when the center axisof a corrective meridian is exactly matched to the desired astigmaticaxis, only a first portion of the cylinder axis is focused at thedesired point of focus (338) (e.g., at the retina) while second portionsof the cylinder axis focuses at other points (340) nearby that areradially offset to the desired point of focus (338). To this end, whenthe primary axis of the astigmatism of the intraocular lens isrotationally offset (shown as arrow 342) with the astigmatism of theeye, the second portion of the cylinder axis focuses the light to thedesired point of focus.

Artificial lenses (e.g., contact lenses or artificial intraocularlenses) can correct for certain visual impairments such as an inabilityof the natural lens to focus at near, intermediate or far distances;and/or astigmatism. Intraocular toric lenses have the potential forcorrecting astigmatism while also correcting for other visionimpairments such as cataract, presbyopia, etc. However, in somepatients, implanted intraocular toric lenses may not adequately correctastigmatism due to rotational misalignment of the corrective meridian ofthe lenses with the astigmatic meridian. In some patients following thesurgical implant of the toric lenses, the corrective meridian of theimplanted toric lenses can be rotationally misaligned to the astigmaticmeridian, in some instances, by as much as 10 degrees. However, toriclenses that are designed to provide maximum correction (e.g., 1D to 9D)at the astigmatic meridian are subject to significant reduction ineffectiveness of the correction due to any misalignment from thecorrective meridian. In certain designs, it is observed that if thecylindrical power axis were mismatched by 1 degree, there would be about3 percent reduction of the effectiveness of the correction. Thedegradation increases with the degree of misalignment. If there were a10-degree misalignment, there would be about 35% reduction of theeffectiveness of the correction. This effect is illustrated in FIG. 4discussed below.

FIGS. 5A and 5B include plots that illustrated the above-discusseddegraded performance of conventional toric lens when subjected torotational misalignments. This conventional toric lens is configured toprovide 6.00 Diopters cylinder powers at the IOL plane, 4.11 Diopterscylinder power at the corneal plane, and a corneal astigmatismcorrection range (i.e., preoperative corneal astigmatism to predictedeffects) between 4.00 and 4.75 Diopters.

Referring to FIG. 5A, a plot of the undesired meridian power (alsoreferred to as a residual meridian power (“OC”)) (shown along they-axis) added due to the rotational misalignments (shown along thex-axis) of the toric IOL is shown, including the residual powers for i)a negative 10-degree misalignment (shown as line 502), ii) a 0-degreemisalignment (shown as line 504), and iii) a positive 10-degreemisalignment (shown as line 506). As shown, the undesired added meridianpower varies between a maximum of ±0.75 Diopters at around the 45-degreemeridian angle (shown as 508) and at about the 135-degree meridian angle(shown as 510). Notably, this undesired added meridian power is outsidethe tolerance of a healthy human eye, which can tolerant undesiredeffects up to about 0.4 Diopters (e.g., at the cornea plane) for normalvisual acuity (i.e., “ 20/20 vision”). Because the undesired effectsexceeds the astigmatism tolerance of the human eye, correctiveprescription glasses, or further surgical operation to correct theimplant misalignment, may be necessary to mitigate the effects of themisalignment of such toric IOLs.

This undesired meridian power may be expressed as Equation 1 below.

$\begin{matrix}{{OC} = {2\mspace{11mu}\sin\mspace{14mu}\alpha*\frac{C}{2}0.7\mspace{11mu}\cos\mspace{11mu}\left( {2\left( {\theta + {90} + \frac{\alpha}{2}} \right)} \right)}} & \left( {{Equation}\mspace{14mu} 1} \right)\end{matrix}$

As shown in Equation 1, θ is the correction meridian (also referred toas the cylindrical power axis) (in degrees); C is the astigmatic power(at the IOL plane) to be corrected at meridian θ (in Diopters); and α isthe magnitude of rotational misalignment of the cylindrical power axisto the astigmatic axis (in degrees).

FIG. 5B shows a plot illustrating the tolerance of a toric IOL tomisalignment (shown in the y-axis) and a corresponding cylindrical powerthat may be applied (shown in the x-axis) for each misalignment to notexceed the astigmatism tolerance of the human eye (i.e., degrade theoverall visual acuity). The tolerance to misalignment may be calculatedas

${\alpha } \leq \sin^{{- 1}\frac{\frac{0.4}{2}}{\frac{C}{0.7}}}$where α is the magnitude of rotational misalignment (in degrees). Thecalculation may be reduced to

${\alpha } \leq {\sin^{{- 1}\frac{{0.2}9}{C}}.}$As shown, for a misalignment of 5 degrees, which is routinely observedin IOL implantations, the correction effectiveness of such IOL implantscan only be maintained for a toric IOL with 3.75 Diopters or less. Thatis, a toric IOL having cylinder power above 3.75 Diopters would exhibitdegraded visual acuity due to the residual power exceeding theastigmatism tolerance of a human eye. This effect is worsen with furtherdegrees of misalignment. For example, at about 10 degrees, theeffectiveness of a toric IOL is greatly reduced where only 1.5 Diopterscylinder power or less can be applied so as to not detrimentally effectthe visual acuity. Given that cylinder power of convention toric IOLsmay range between 1.00 Diopters and 9.00 Diopters, these toric IOLs arereduced in effectiveness post-operation due to the misalignments ofcylinder axis.

Each of FIGS. 6A and 6B shows plots illustrating modular transferfunctions (MTFs) in white light for two toric IOLs (shown as 602 a and602 b) each configured with angularly-varying phased members whensubjected to off-axis rotations. FIG. 6A illustrates the performance fora refractive toric IOL, and FIG. 6B illustrates performance for adiffractive toric IOL.

Remarkably, the cylinder power of the lens configured with angularlyvarying phase members provides an extended tolerance of misalignment upto 10 degrees, and more, of off-axis rotation. As shown in FIGS. 6A and6B, the modulation transfer function (MTF) is maintained across theextended range of alignment fora lens configured with the angularlyvarying phase members. In contrast, at certain degrees of misalignment,the MTF of a toric IOL (shown as lines 604 a and 604 b) without theangularly varying phase member is near zero. For example, as shown inFIG. 6A, the MTF at about 3.5 degrees misalignment for a conventionaltoric lens is near zero. MTF is a modulation of the amplitude and phasefunctions of an image formed by the white light on a specified plane,e.g., the retina of the human eye, and characterizes the sensitivity ofthe lens.

Referring still to FIGS. 6A and 6B, an ophthalmic apparatus thatincludes angularly varying phase members has a lower maximum cylinderrange (as compared to lens without such structure). Rather, theangularly varying phase members apply the cylinder power to a bandsurrounding the corrective meridian, thereby providing a continuous bandthat makes the lens may tolerant due to misalignment. As shown, in thisembodiment, the sensitivity of the ophthalmic apparatus with theangularly varying phase members is less by 20% as compared to a lenswithout the angularly varying phase members. And, at 10 degrees ofmisalignment (or off-axis operation) from the targeted corrective axis,the modulation transfer function (MTF) degradation for the ophthalmicapparatus configured with the angularly varying phase member is stillacceptable. In this example, the ophthalmic apparatus configured withthe angularly varying phase members is configured as a monofocal toriclens with 4.0 Diopters cylindrical power. Here, the MTF is at 1001p/−mmand has a spatial frequency equivalent to 30 c/degree for an emmetropiaeye with 20/20 visual acuity. The performance of the toric IOL with theangularly varying phase member at 5 degrees off-meridian (e.g., line 602a) has comparable MTF performance to a similar toric IOL without theangularly varying phase structure at 2 degrees of misalignment (e.g.,line 604 a).

FIGS. 7A and 7B are diagrams of an ophthalmic apparatus 100 (e.g., anintraocular toric lens) that includes angularly-varying phase members102 (reflective, diffractive, or both) that disperse light therethroughto a plurality of foci that are offset radially to one another so as toprovide an extended tolerance to misalignments of the lens 100 whenimplanted in an eye in accordance with another illustrative embodiment.As shown in FIGS. 7A-7B, the apparatus 100 has an asymmetric heightprofile 702 in which the maximum height of the face of the apparatusdiffers between the different zones. To demonstrate the asymmetricheight profile 702, representative echelette in zones 102 b and 102 c ofan example refractive surface is shown. In zone 102 b, the height of arepresentative echelette 704 is shown to be greater than the height of arepresentative echelette 706 in zone 102 c.

In some embodiments, the asymmetric height profile 702 may be configuredto direct light to a plurality foci. For example, the apparatus 100 withthe asymmetric height profile 702 may be used for as a trifocal lens. Inother embodiments, the apparatus with the asymmetric height profile 702is used for a quad-focal lens. In some embodiments, the apparatus 100with the asymmetric height profile 702 is used for a double bi-focallens. In some embodiments, the apparatus 100 with the asymmetric heightprofile 702 is used for a mono-focal lens. In some embodiments, theapparatus 100 with the asymmetric height profile 702 is used for acombined bi-focal and tri-focal lens. In some embodiments, the apparatus100 with the asymmetric height profile 702 is used for an anteriorbifocal and a posterior tri-focal lens. In some embodiments, theapparatus 100 with the asymmetric height profile 702 is used for aposterior bifocal and an anterior tri-focal lens.

FIGS. 8 and 9 illustrate a plurality of height profiles of theangularly-varying phase members 102 of the lens in accordance withvarious illustrative embodiments. As shown in FIG. 8, the height profileis symmetric at each meridian in that the maximum height (shown as 802,804, and 806) at the face of the lens are the same. As shown in FIG. 9,the height profile is asymmetric in that the maximum height at the faceof the lens are different.

FIG. 10 illustrates an example multi-focal intraocular lens 1000configured with angularly varying phase members in accordance with anillustrative embodiment. As shown, the lens 1000 provides a mono-focalat corrective meridian Θ=0° and 180°. In addition, the lens 1000provides a second mono-focal at corrective meridian Θ=90° and −90°. Inaddition, the lens 1000 provides a first bi-focal at Θ=−45° and 135°. Inaddition, the lens 1000 provides a second bi-focal at Θ=45° and −135°.In some embodiments, the lens is refractive. In other embodiments, thelens is diffractive.

With the angularly varying phase members, images at all meridians (Θ=0°,Θ=45°, Θ=90°, Θ=135°, Θ=180°, Θ=−135°, Θ=−90°, and Θ=−45°) reach a 20/20“uncorrected distance visual acuity” (UDVA). FIGS. 11 and 12 arediagrams illustrating added cylindrical power, from the angularlyvarying phase members, in the radial and angular position in accordancewith the illustrative embodiments.

FIG. 11 illustrates added cylinder power by the angularly varying phasemembers for a multi-focal intraocular lens configured as a bifocal. Asshown in FIG. 11, for a given cylindrical power (e.g., 6.0 Diopters),the angularly varying phase members add varying magnitudes of cylinderpowers between, e.g., 0.125 Diopters and 1.0 Diopter between the peakcorrective meridian Θ=0° (e.g., the astigmatic meridian) and thenon-peak corrective meridian Θ=45° in which minimum cylinder power isadded at Θ=0° (where the meridian is a mono-focal, shown at points1102), and in which the maximum cylinder power is added at Θ=45° wherethe meridian is configured as a bi-focal (shown along line 1104). Theadded power to the non-peak corrective meridian increases the toleranceof the IOL to misalignment from the corrective axis.

FIG. 12 illustrates a trifocal intraocular lens with the angularlyvarying phase members in accordance with an illustrative embodiment. Asshown in FIG. 12, the added varying cylinder power is added between thepeak corrective meridian Θ=0° and the non-peak corrective meridianΘ=45°, as shown in FIG. 11. As further shown, a trifocal optics 1202 isadded. The trifocal 1202 does not have an angularly varying phasemember.

FIG. 13 illustrates an ophthalmic apparatus 1300 having angularlyvarying phase members to extend tolerance of ocular astigmatism byvarying extended depth of focus at each meridian through an optimizedcombination of angularly and zonally diffractive phase structure on eachmeridian in accordance with an illustrative embodiment.

As shown in FIG. 13, the ophthalmic apparatus 1300 includes a firstcorrective meridian 90°*N°±α° (variable 01), where α is the extendedtolerance of the first corrective meridian, and N is an integer. ForN=0, 1, 2, 3, 4, the meridians includes 0° (1302), ±90° (1304), and 180°(1306). In some embodiments, α is ±3°, ±3.25°, ±3.5°, ±3.75°, ±4°, ±4°,±4.25°, ±4.5°, ±4.75°, ±5°, ±5.25°, ±5.5°, ±5.75°, ±6°, ±6.25°, ±6.5°,±6.75°, ±7°, ±7.25°, ±7.5°, ±7.75°, ±8°, ±8.25°, ±8.5°, ±8.75°, ±9°,±9.25°, ±9.5°, ±9.75°, and ±10°. Where α is ±10°, the IOL would have adynamic and optimized efficiency for correcting astigmatic effects thatcan tolerate misalignment of the cylindrical axis up to 10 (variable 08)degrees in either counter clockwise or clockwise rotation. It iscontemplated that terms noted as variables may be varied, modified, oradjusted, in some embodiments, to produce desired or intended effectsand benefits, as discussed herein.

FIG. 14 illustrates a table for a trifocal IOL configured with theangularly varying phase members. As shown in FIG. 14, the lighttransmission efficiency at a first corrective foci 1402 (e.g., at theretina) is about 100% while other foci along the same meridian is about0%. This configuration establishes the first corrective meridian 1402 atθ=0° and other meridians, e.g., θ=±90° and, e.g., 180°, as a monofocalwith additional chromatic aberration reduction.

In addition, at meridian 45°*N°±α° (1408 and 1410) (variable 02), thelight transmission efficiency varies for three point of focus (shown as1408 a, 1408 b, and 1408 c) (e.g., at the front of the retina, at theretina, and behind the retina) of the optics at this meridian. For N=1,2, 3, 4, the meridians includes ±45° and ±90°. As shown in FIG. 14, atthe first foci (1408 a) (e.g., at the front of the retina), the lighttransmission efficiency is about 25% (variable 03), and the opticsincludes added power that matches the ocular astigmatic powercorresponding to the human astigmatism tolerance level. At the secondfoci (1408 b) (e.g., at the retina), the light transmission efficiencyis about 50% (variable 04) efficiency. At the third foci (1408 c) (e.g.,behind the retina), the light transmission efficiency is about 25%(variable 05), and the optics include added power having the samemagnitude as the first foci though with an opposite sign. At othermeridians, the focus on the retina has efficiency between 0.5% and 100%(variable 06) and the other focus not on the retina has efficiencybetween 0% and 25% (variable 07). In some embodiments, the lighttransmission efficiency are varied via different materials that may bestacked, e.g., as a stacking lens, where each layer is comprised of adifferent material. In other embodiments, the angularly-varying phasemembers may be comprised of a material or materials that have avariation in refractive index, a gradient index, or a programmed index,for example liquid crystal which creates transmission efficiency change.

The thickness profile T₁(r, θ) for the IOL may be characterized byEquation 2 below.T ₁(r,θ)=t ₁(r)|COS²(θ)|+t ₂(r)|SIN²(θ)|  (Equation 2)

According to Equation 2, t₁(r) and t₂(r) are step heights for each zone,and they each matches an optical path difference (OPD) from −2λ to 2λ,where λ is the design wavelength at zonal radius r.

Equation 2 may be simplified and represented as Equation 3, where A isadjusts the size of the extended operating band of the angularly varyingphase member, and B provides an offset of the center of the angularlyvarying phase member with respect to a pre-defined reference frame(e.g., Θ=0° or Θ=90°, etc.).T ₁(r,θ)=COS[Aθ+B]  (Equation 3)

Example: Angularly Varying Phase Members That Varies Along AngularPosition

FIGS. 15-18, comprising, FIGS. 15A, 15B, 16A, 16B, 16C, 17A, 17B, 18A,18B, and 18C, depict the ophthalmic apparatus with angularly varyingphase members in accordance with other illustrative embodiments.According to these embodiments, the angularly varying phase members arelocated with a fixed-size zone and varies only along the angularposition. In FIGS. 15A, 15B, 16B, 16C, 17A, 17B, 18B, and 18C, heightprofiles are illustrated via representative echelette elements for adiffractive surface.

As shown in FIGS. 15A-15B, the ophthalmic apparatus includes a pluralityof zones 1502 (shown as 1502 a, 1504 b, and 1504 c). The zones 1502 a,1502 b, 1502 c defined at a first corrective meridian θ=0° and 180°(1506) has approximately the same zone length (i.e., cylinder power) asthe zones 1502 a, 1502 b, 1502 c defined at a second meridian θ=45° and135° (1508). As further shown in FIGS. 16A, 16B, and 16C, the heightprofile (shown as 1602, 1604, 1606, 1608, 1610, and 1612) of the face ofthe lens varies along the angular position θ=0°, θ=9°, θ=18°, θ=27°,θ=36°, and θ=45°.

FIGS. 17A and 17B illustrate an ophthalmic apparatus having a heightprofile across the multiple zones (shown as 1702 a, 1702 b, and 1702 c)in which the height of the face of the lens angularly varies with themeridian axes. As shown in FIGS. 18A, 18B, and 18C, the height profile(shown as 1802, 1804, 1806, 1808, 1810, and 1812) of the face of thelens varies along the angular position θ=0°, θ=9°, θ=°, θ=27°, θ=36°,and θ=45°.

Referring back to FIG. 13, in another aspect, the ophthalmic apparatusincludes a plurality of alignment markings, including a first set ofalignment markings 1302 and a second set of alignment markings 1304,that indicate the corrective meridian of the lens. In some embodiments,the first set of alignment markings 1302 is located at the meridian θ=0°and 180°. The second set of alignment markings 1304 may includecorresponding sets of markets to define a tolerance band for the lens.In some embodiments, the second set of alignment markings 1304 islocated at ±5° radial offset from the first set of alignment markings1302.

Example: Refractive Lens Surfaces with Angularly Varying Phase Members

FIGS. 19A and 19B are diagrams of an exemplary ophthalmic apparatus 1900that includes refractive angularly-varying phase members 102 inaccordance with another illustrative embodiment. A height profile 1902(shown as 1902 a and 1902 b) of the refractive surface 1904 (shown as1904 a and 1904 b) is shown at Θ=0° and Θ=45°. As shown in FIG. 19A, thefirst height profile 1902 a of the lens transitions into the secondheight profile 1904 b. Here, the inflection point of the refractivesurface is shown to vary spatially (i.e., changing radial values) andangularly (i.e., changing height or thickness values).

FIGS. 20A, 20B, 20C, 20D, and 20E illustrate a plurality of exemplaryheight profiles of the anterior or posterior face across the angularlyphase members of the ophthalmic apparatus of FIGS. 19A-19B, inaccordance with an illustrative embodiment. That is, the height profileis shown between the first high power meridian (at Θ=0°) and theoperational edge of the angularly varying phase members (e.g., at Θ=±α,e.g., Θ=10° and Θ=−10°) in accordance with an illustrative embodiment.In FIG. 20B, representative height profiles at Θ=0° (2002); Θ=2° (2004);Θ=4° (2006); Θ=6° (2008); Θ=8° (2010); and Θ=10° (2012) (also shown inFIG. 20A) are provided as cross-sections of the echelette at thedifferent meridians shown in FIG. 20A. As shown, the height profiles ataxes nearby to the first high power meridian (e.g., between ±10°) have asimilar shape, as the first high power meridian. The height profilevaries in a continuous gradual manner (e.g., having a sine and cosinerelationship) along the radial direction. This can be observed in FIGS.20B and 20C. In FIG. 20B, the overall refractive profile is shown, andin FIG. 20C, an inflection point 2014 (e.g., shown as points 2014 a,2014 b, 2014 c, 2014 d, 2014 e, and 2014 f) defined at a given zoneboundary is shown. This transition of the inflection points 2014 may bedescribed as a cosine-based or sine-based function, or a functionderived from a combination thereof.

The thickness profile T1(r, θ) for the refractive design may becharacterized by Equation 4 below.T1(r,θ)=t ₁(r)|COS²(θ)|+t ₂(r)|SIN²(θ)|  (Equation 4)

According to Equation 4, t₁(r) and t₂(r) are the add power for eachzone, and they each match optical power needs from −200D to +5.0D, for adesign wavelength at zonal radius r.

FIG. 20C illustrates a first portion of the height profiles (near theoptical axis) at Θ=0° (202); Θ=2° (204); Θ=4° (206); Θ=6° (208); Θ=8°(210); and =10° (212) superimposed next to one another. This variationof the height profile along the radial axis provides a lens region thatfocuses light at the desired foci and other foci nearby. To this end,radial offset (i.e., misalignment) of the ophthalmic apparatus from thecenter axis of a desired corrective meridian results in its nearbyregions focusing the light to the desired foci.

In FIGS. 20D and 20E, example height profiles of the lens surfacebetween Θ=0° and Θ=45° are shown. As shown in FIGS. 20D and 20E, theheight profiles of the angularly varying phase member vary as acosine-based or sine-based function. In some embodiments, the heightprofiles of the lens surface between Θ=45° and Θ=90° are mirrored atΘ=45° to the lens surface between Θ=0° and Θ=45°.

It is contemplated that refractive angularly varying phase member canvary symmetrically or asymmetrically, for a given zone, as well asbetween the multiple zones, as described, for example, in relation toFIGS. 8, 9, 16, and 18. That is, inflection points in the refractivesurface at a given zone (e.g., a first zone) may vary, in the radial andangular direction, at the same rate with inflection points in therefractive surface at another zone (e.g., a second zone), as describedin relation to the diffractive element of FIG. 8. In addition, in someembodiments, inflection points in the refractive surface at a given zone(e.g., a first zone) may vary, in the radial and angular direction, at adifferent rate with inflection points in the refractive surface atanother zone (e.g., a second zone), as described in relation to thediffractive element of FIG. 9. In addition, in some embodiments,inflection points in the refractive surface at a given zone (e.g., afirst zone) may vary, only in the angular direction, at a same ordifferent rate with inflection points in the refractive surface atanother zone (e.g., a second zone), as described in relation to thediffractive element of FIGS. 16 and 18.

Example: Multi-Focal Refractive Ophthalmic Apparatus with Diffractive orRefractive Angularly Varying Phase Members

FIGS. 21A, 21B, and 21C are diagrams illustrating an exemplaryophthalmic apparatus 2100 that includes refractive or diffractiveangularly-varying phase members 102, in accordance with anotherillustrative embodiment.

The angularly-varying phase member 102, in FIG. 21, can be characterizedas Equation 5, where r(θ) is the contour radius for the given meridianadded power A(θ), wavelength λ, zone number n, and the scaling values(θ), all at meridian θ.

$\begin{matrix}{{r(\theta)} = \sqrt{2 \cdot n \cdot \frac{{s(\theta)} \cdot \lambda}{A(\theta)}}} & \left( {{Equation}\mspace{14mu} 5} \right)\end{matrix}$

In FIG. 21A, the lens 2100 provides a mono-focal at corrective meridianΘ=0° and 180°. In addition, the lens 2100 provides a second mono-focalat corrective meridian Θ=90° and −90°. In some embodiments, themono-focal corrective meridian Θ=0° and 180° and the mono-focalcorrective meridian Θ=90° and −90° have the same focal point. In otherembodiments, the mono-focal corrective meridian Θ=0° and 180° and themono-focal corrective meridian Θ=90° and −90° have different focalpoints.

Referring still to FIG. 21A, the lens 2100 provides a first bi-focal atΘ=−45° and 135° and, in addition, the lens 2100 provides a secondbi-focal at Θ=45° and −135°. In some embodiments, the bi-focalcorrective meridian −45° and 135° and the bi-focal corrective meridianΘ=45° and −135° have the same focal point. In other embodiments, thebi-focal corrective meridian −45° and 135° and the bi-focal correctivemeridian 45° and −135° have different focal points.

As shown in FIG. 21B, intraocular lens 2100 has a base cylindrical power(e.g., 6.0 Diopters) to which angularly varying phase members havingadditional cylindrical power are added. The angularly varying phasemembers adds the cylindrical power having an extended tolerance ofoperation, for example, up to ±10° (of misalignment) from a givencorrective meridian (e.g., an astigmatism meridian). As shown, theadditional cylindrical power are added to a surface sag coordinate(shown as “sag(z)”). Specifically, the added cylindrical power (shown as“Value θ” in FIG. 21B), for each given angular position θ (2104), inthis exemplary lens design, varies between about −200 Diopters and about−0.01 Diopters (shown as “Value θ” 2104) and between about 0.01 Dioptersand about 6.0 Diopters (shown as “Value θ” 2106). The added power isprovided over the surface of the intraocular lens having a diameter 2108of 6.0 mm (millimeters). Radial positions 2114 (shown as 2114 a and 2114b) are illustratively shown in FIGS. 21A and 21B. As shown in FIG. 21C,the added cylindrical power, along each radial positions (e.g., atΘ=−180° to Θ=180°), at radial positions 2114 a and 2114 b are provided.

Referring still to FIG. 21B, the added cylindrical power of 0.01Diopters and about 6.0 Diopters and of −200 Diopters and about −0.01Diopters is added via a refractive surface 2110 (e.g., as shown havingan “ETA(r, θ) surface profile”). As shown in FIG. 21B, the refractivesurface 2110 has a modified thickness value at sag surface value of “0”at the center of the lens. The sag surface value, as shown, decreases togenerate the refractive surface profile, as for example, described inrelation to FIG. 4D. It should be appreciated that the provided sagsurface profile is merely illustrative. It is contemplated thatequivalent refractive surfaces may be produced on various lens surfacein additive or subtractive manner, as shown, for example, but notlimited to, in relation to FIGS. 4A-4D.

Referring still to FIG. 21B, the added cylindrical power profile 2112may be used to provide distant vision and emmetropia correction for agiven patient. Emmetropia generally refers to a state in which the eyeis relaxed and focused on an object more than 20 feet away in whichlight coming from the focus object enters the eye in a substantiallyparallel, and the rays are focused on the retina without effort. To thisend, image at all meridian can reach 20/20 “uncorrected distance visualacuity” (UDVA).

Referring to back to FIG. 21A, the added cylindrical power profile 2112of FIG. 21B is added at angular position Θ=Θ° (shown as “Θ=Θ° 2116”). Tothis end, the angularly varying phase members, as described herein, forexample, including those described in relation to FIGS. 1-2, 7-9, and15-20 may be applied at any angular position along the lens surface, togenerate a multi-focal lens.

Referring still to FIG. 21A, in some embodiment, a complementaryangularly varying phase member may be added in a given quadrant of thelens. For example, an intraocular lens may include a first angularlyvarying phase member at an angular position between Θ=45° and Θ=90°; theintraocular lens may include a second angularly varying phase member atan angular position between Θ=0° and Θ=45° in which the second angularlyvarying phase member is mirrored, along the axis Θ=45°, with respect tothe first angularly varying phase member.

Example: Alignment Markings for Extended Tolerance Band

FIGS. 22A and 22B depicts an ophthalmic apparatus with an extendedtolerance astigmatic band. The ophthalmic apparatus includes the secondset of alignment markings 1308 as discussed in relation to FIG. 13.

FIG. 23 is diagram of a method 2300 to generate, via a processor, thesurface with the angularly-varying phase members, in accordance with anillustrative embodiment. As shown in FIG. 23, the method 2300 includesgenerating (2302), via a processor, an initial design (2304) comprisinga base surface (with base cylindrical power) and sectional enhancements(with added cylindrical power) and iteratively generating (2308) andevaluating, a revised design (2310), generated according to anoptimization routine (2308) that is performed based on sectionalparameters, until pre-defined image quality metric values and boundaryparameter are achieved. The sectional enhancements power of the initialdesign and the iterative design is the surface with theangularly-varying phase members.

Referring still to FIG. 23, the method 2300 includes generating (2302) afirst design (2304) via i) initial surface optical parameter, includinga) base surface optical parameters 2312 and b) sectional surface opticalparameters 2314, and ii) the pre-defined image quality metric values2316. The base surface optical parameters 2312 include, in someembodiments, parameters associated with a radius of curvature for thetoric lens (shown as “Radius of curvature” 2318), parameters associatedwith conic constant and aspheric coefficients (shown as “Conicconstant”2320), parameters associated with base cylinder power (shown as“Cylinder power” 2322), and parameters associated lens and/or coatingmaterial characteristics such as refractive index (shown as “Refractiveindex” 2324). Other parameters may be used as part of the base surfaceoptical parameters 2312. The section surface optical parameters 2314, insome embodiments, includes parameters associated with sectional addedpower and meridian characteristics (shown as “Sectional add power” 2328)and parameters associated with high order aberration characteristics,e.g., Zernike aberrations above second-order (shown as “High orderaberrations” 2328).

Referring still to FIG. 23, the parameters associated with the sectionaladded power 2326, in some embodiments, include a cylindrical power, fora given optical zone. In some embodiments, the cylindrical power for theadded power are all refractive, all diffractive, or a combination ofboth. The parameters associated with the high order aberrationcharacteristics 2328, in some embodiments, include polynomial values(e.g., based on Zernike polynomials, Chebyshev polynomials, andcombinations thereof) or characteristics such as polynomial orders andtypes as well as meridian boundaries for the high order aberrations. Thehigh order aberration is constraint, e.g., from minimum to maximumcylindrical power over one or more meridian sections. In someembodiments, the high order aberrations is constraint or designated to ameridian, e.g., that corresponds to a corneal irregular geometry orlimited retinal area functions. Such customization has a potential totruly benefit patients having cornea with or without astigmatism,patients with local Keratoconus with or without astigmatism, patientswith glaucoma, patients with retinal macular degeneration (AMD), and thelike.

Referring still to FIG. 23, the parameters associated with thepre-defined image quality metric value 2316 includes parametersassociated with expected image quality metric (shown as “Expected imagequality metric values” 2330) and parameters associated with specialboundary restrain parameters (shown as “Special boundary restrainparameters” 2332). In some embodiments, image quality metric is based acomparison of a base polychromatic diffraction MTF (modular transferfunction) (e.g., tangential and sagittal) to a number of errorpolychromatic diffraction MTFs values, e.g., where one or morepolychromatic diffraction MTFs are determined for one or moremisalignments of the generated tonic lens from its intended operatingmeridians, e.g., at 5-degree misalignment and at 10-degree misalignment.

Referring still to FIG. 23, the initial design (2304) is evaluated (2334a) to determine image quality metric values (e.g., the basepolychromatic diffraction MTF, e.g., at 0 degree misalignment) and theerror polychromatic diffraction MTFs, e.g., at the 5 and 10 degreesmisalignment) and boundary parameters. The determined image qualitymetric values are evaluated (2336) to determine whether the imagequality metric values and boundary parameters meet an expected outcome,e.g., a value of 0.2. In some embodiments, the expected outcome iswhether there is no cut off through spatial frequency beyond 100 cpd.Upon determining that the condition is met, the method 2300 is stop(2338). It is contemplated that other image quality metrics may be used,e.g., the optical transfer function (OTF), phase transfer function(PhTF), and etc.

Where the condition is not met, the method adjusts (2308) sectionalparameters to be optimized and rerun the optimization to generate therevised design 2310. In some embodiments, the adjusted sectionalparameters may include power A(θ), wavelength λ, zone number n, and thescaling value s(θ), as for example, shown in FIGS. 19A-19B, 20A-20E,21A-21C, which is expressed as

${{r(\theta)} = \sqrt{2 \cdot n \cdot \frac{{s(\theta)} \cdot \lambda}{A(\theta)}}},$where r(θ) is the contour radius for the given meridian added powerA(θ), wavelength λ, zone number n, and the scaling value s(θ), all atmeridian θ.

Referring back to FIG. 23, the method 2300 then includes evaluating(2334 b) the revised design 2310 to determine image quality metricvalues (e.g., the base polychromatic diffraction MTF, e.g., at 0 degreemisalignment) and the error polychromatic diffraction MTFs, e.g., at the5 and 10 degrees misalignment) and boundary parameters, as discussed inrelation to step 2334 a, and re-evaluating (2336) whether the revisedimage quality metric values and boundary parameters meet the expectedoutcome, as discussed in relation to step 2336.

In some embodiments, the method 2300 is performed in an optical andillumination design tool such as Zemax (Kirkland, Wash.). It iscontemplated that the method 2300 can be performed in other simulationand/or design environment.

The present technology may be used, for example, in the Tecnis toricintraocular lens product line as manufactured by Abbott Medical Optics,Inc. (Santa Ana, Calif.).

It is not the intention to limit the disclosure to embodiments disclosedherein. Other embodiments may be used that are within the scope andspirit of the disclosure. In some embodiments, the above disclosedangularly varying phase members may be used for multifocal toric,extended range toric, and other categorized IOLs for extended toleranceof astigmatism caused by factors including the cylindrical axismisalignment. In addition, the above disclosed angularly varying phasemembers may be applied to spectacle, contact lens, corneal inlay,anterior chamber IOL, or any other visual device or system.

Exemplary Computer System

FIG. 24 is a diagram of an example computing device configured togenerate the surface with the angularly-varying phase members. As usedherein, “computer” may include a plurality of computers. The computersmay include one or more hardware components such as, for example, aprocessor 2421, a random access memory (RAM) module 2422, a read-onlymemory (ROM) module 2423, a storage 2424, a database 2425, one or moreinput/output (I/O) devices 2426 and an interface 2427. Alternativelyand/or additionally, controller 2420 may include one or more softwarecomponents such as, for example, a computer-readable medium includingcomputer executable instructions for performing a method associated withthe exemplary embodiments. It is contemplated that one or more of thehardware components listed above may be implemented using software. Forexample, storage 2424 may include a software partition associated withone or more other hardware components. It is understood that thecomponents listed above are exemplary only and not intended to belimiting.

Processor 2421 may include one or more processors, each configured toexecute instructions and process data to perform one or more functionsassociated with a computer for indexing images. Processor 2421 may becommunicatively coupled to RAM 2422, ROM 2423, storage 2424, database2425, I/O devices 2426, and interface 2427. Processor 2421 may beconfigured to execute sequences of computer program instructions toperform various processes. The computer program instructions may beloaded into RAM 2422 for execution by processor 2421. As used herein,processor refers to a physical hardware device that executes encodedinstructions for performing functions on inputs and creating outputs.

RAM 2422 and ROM 2423 may each include one or more devices for storinginformation associated with operation of processor 2421. For example,ROM 2423 may include a memory device configured to access and storeinformation associated with controller 2420, including informationassociated with IOL lenses and their parameters. RAM 2422 may include amemory device for storing data associated with one or more operations ofprocessor 2421. For example, ROM 2423 may load instructions into RAM2422 for execution by processor 2421.

Storage 2424 may include any type of mass storage device configured tostore information that processor 2421 may need to perform processesconsistent with the disclosed embodiments. For example, storage 2424 mayinclude one or more magnetic and/or optical disk devices, such as harddrives, CD-ROMs, DVD-ROMs, or any other type of mass media device.

Database 2425 may include one or more software and/or hardwarecomponents that cooperate to store, organize, sort, filter, and/orarrange data used by controller 2420 and/or processor 2421. For example,database 2425 may store hardware and/or software configuration dataassociated with input-output hardware devices and controllers, asdescribed herein. It is contemplated that database 2425 may storeadditional and/or different information than that listed above.

I/O devices 2426 may include one or more components configured tocommunicate information with a user associated with controller 2420. Forexample, I/O devices may include a console with an integrated keyboardand mouse to allow a user to maintain a database of images, updateassociations, and access digital content. I/O devices 2426 may alsoinclude a display including a graphical user interface (GUI) foroutputting information on a monitor. I/O devices 2426 may also includeperipheral devices such as, for example, a printer for printinginformation associated with controller 2420, a user-accessible diskdrive (e.g., a USB port, a floppy, CD-ROM, or DVD-ROM drive, etc.) toallow a user to input data stored on a portable media device, amicrophone, a speaker system, or any other suitable type of interfacedevice.

Interface 2427 may include one or more components configured to transmitand receive data via a communication network, such as the Internet, alocal area network, a workstation peer-to-peer network, a direct linknetwork, a wireless network, or any other suitable communicationplatform. For example, interface 2427 may include one or moremodulators, demodulators, multiplexers, demultiplexers, networkcommunication devices, wireless devices, antennas, modems, and any othertype of device configured to enable data communication via acommunication network.

While the methods and systems have been described in connection withpreferred embodiments and specific examples, it is not intended that thescope be limited to the particular embodiments set forth, as theembodiments herein are intended in all respects to be illustrativerather than restrictive.

Unless otherwise expressly stated, it is in no way intended that anymethod set forth herein be construed as requiring that its steps beperformed in a specific order. Accordingly, where a method claim doesnot actually recite an order to be followed by its steps or it is nototherwise specifically stated in the claims or descriptions that thesteps are to be limited to a specific order, it is no way intended thatan order be inferred, in any respect. This holds for any possiblenon-express basis for interpretation, including: matters of logic withrespect to arrangement of steps or operational flow; plain meaningderived from grammatical organization or punctuation; the number or typeof embodiments described in the specification.

What is claimed is:
 1. A rotationally-tolerant intraocular lens (IOL)for correcting astigmatism, the intraocular lens comprising: amulti-zonal lens body comprising one or more angularly-varying phasemembers that each includes an optimized combination of angularly andzonally refractive phase structure located across one or more opticalzones to apply cylinder power at one or more correcting meridian,wherein each of the one or more angularly-varying phase members appliescylinder power at a given correcting meridian and vary an extended depthof focus to a plurality of nearby points of focus to provide an extendedtolerance to misalignment of the intraocular lens when implanted in aneye, wherein the multi-zonal lens body forms a first angularly-varyingphase member having a peak cylinder power centered at a first correctingmeridian, the first angularly-varying phase member at the peak cylinderpower being configured to direct light, at the first correctingmeridian, to a first point of focus on the retina, wherein at angularpositions nearby to the first correcting meridian, the firstangularly-varying phase member varies, at each optical zone, and isconfigured to direct light to points of focus nearby to the first pointof focus such that the multi-zonal lens body, when rotational offsetfrom the peak cylinder power, directs light from the nearby points offocus to the first point of focus, thereby establishing an extended bandof operational meridians over the first correcting meridian, and whereinthe multi-zonal lens body forms a second angularly-varying phase memberat a second meridian, wherein the second meridian is orthogonal to thefirst meridian.
 2. The intraocular lens of claim 1, wherein theangularly and zonally refractive phase structure has a height profile ata face of the intraocular lens that angularly varies along each meridiannearby to the center of the first meridian.
 3. The intraocular lens ofclaim 2, wherein the height profile of the angularly and zonallyrefractive phase structure angularly varies in a continuous gradualmanner.
 4. The intraocular lens of claim 2, wherein the height profile,for each meridian θ is defined as:T1(r,θ)=t ₁(r)|COS²(θ)|+t ₂(r)|SIN²(θ)| where t₁(r) and t₂(r) are theadded power for each zone.
 5. The intraocular lens of claim 1, whereinthe angularly and zonally refractive phase structure angularly variesalong each meridian nearby to the center of the first meridian up to apre-defined angular position of the intraocular lens.
 6. The intraocularlens of claim 5, wherein the pre-defined angular position is at leastabout 5 degrees from the center of the first meridian.
 7. Theintraocular lens of claim 1, wherein the angularly and zonallyrefractive phase structure varies along each correcting meridian betweenthe first meridian and a second meridian that is about 45 degrees offsetto the first meridian and between the first meridian and a thirdmeridian that is about −45 degrees offset to the first meridian.
 8. Theintraocular lens of claim 7, wherein each of i) the second meridianlocated about 45 degrees from first meridian and ii) the third meridianlocated about −45 degrees from the first meridian, collectively, form abifocal lens.
 9. The intraocular lens of claim 1, wherein themulti-zonal lens body comprises at least three optical zones, the atleast three optical zones forming an angularly varying efficiencytrifocal optics.
 10. The intraocular lens of claim 1, wherein themulti-zonal lens body comprises at least four optical zones, the atleast four optical zones forming an angularly varying efficiency quadricoptics.
 11. The intraocular lens of claim 1, wherein the firstangularly-varying phase member and the second angularly-varying phasemember, collectively, form an angularly varying efficiency bifocaloptics.
 12. The intraocular lens of claim 1, wherein the secondangularly-varying phase member has a center at the second meridian, thesecond angularly-varying phase member varying along each meridian nearbyto the center of the second meridian i) between the second meridian anda third meridian that is about 45 degrees offset to the second meridianand ii) between the second meridian and a fourth meridian that is about−45 degrees offset to the second meridian.
 13. The intraocular lens ofclaim 1, wherein the intraocular lens comprises an intraocular toriclens.
 14. The intraocular lens of claim 13, wherein theangularly-varying phase members, collectively, form a pattern that isexpressed as${{r(\theta)} = \sqrt{2 \cdot n \cdot \frac{{s(\theta)} \cdot \lambda}{A(\theta)}}},$where r(θ) is the contour radius for the given meridian added powerA(θ), wavelength λ, zone number n, and the scaling value s(θ), all atmeridian θ.
 15. The intraocular lens of claim 1, wherein the firstangularly-varying phase member comprises a monofocal lens.
 16. Theintraocular lens of claim 1, wherein the second angularly-varying phasemember comprises a second monofocal lens.
 17. The intraocular lens ofclaim 1, wherein the first angularly-varying phase member establishesthe band of operational meridians across a range selected from the groupconsisting of about +4 degrees, about +5 degrees, about +6 degrees,about +7 degrees, about +8 degrees, about +9 degrees, about +10 degrees,about +11 degrees, about +12 degrees, about +13, degrees, about +14degrees, and about ±15 degrees.
 18. The intraocular lens of claim 1,further comprising: a plurality of alignment markings, including a firstset of alignment markings and a second set of alignment markings,wherein the first set of alignment markings corresponds to the center ofthe first meridian, and wherein the second set of alignment markingscorresponds to the band of operational meridians.